Max Jarman
The Arizona Republic
Jun. 1, 2006 12:00 AM
Research under way at Northern Arizona University could make it safer to mine and handle uranium in Arizona and around the world.
A project led by NAU biochemist Diane Stearns has found that uranium's heavy-metal properties can make people sick, independently of the element's radiation and radon gas.
The findings have far-reaching implications for people living near abandoned uranium mines in the Southwest and for the military, which uses depleted, or "non-radioactive," uranium for anti-tank weapons, tank armor and ammunition rounds.
"People assume that if the uranium is not radioactive, it's harmless," Stearns said. "We're finding that's not the case."
Heavy metals are metallic elements with high atomic weights, such as mercury, cadmium, arsenic and lead. If they get into the bloodstream, they can bind with DNA particles to interrupt cellular communication and cause diseases.
The Environmental Protection Agency and the Nuclear Regulatory Commission treat depleted uranium as a hazardous material, but the Department of Defense continues to use it. The department also has declined to clean it up from military sites.
The harmful effects of heavy metals such as mercury and lead are well known, but Stearns and her team are the first to identify this trait in uranium and to show that when it binds with DNA, the cells acquire mutations.
Stearns is optimistic that the research could lead to new rules for handling depleted uranium. It also could lead to tests for exposure to the heavy-metal properties of uranium as well as the radiation and radon gas it emits as it decays.
But the program, funded by the Native American Cancer Research Project, has another benefit. It is helping young Navajos come to terms with the tragic effects and lingering health hazards brought by earlier uranium mining on their vast reservation in Arizona and New Mexico.
Widespread and largely unregulated uranium mining on the reservation from the 1940s through 1960 left the Navajos with a legacy of disease, death and fear. A number of Navajo researchers are working on Stearns' team and are gaining knowledge they can take back to the reservation to help others.
Hertha Woody, a 26-year-old research assistant in Stearns' laboratory, grew up in Shiprock, N.M., not far from a huge mound of uranium tailings left by an abandoned mill.
"I grew up seeing this pile, and I knew it could make people sick," Woody said. "But I didn't know why."
Working with Stearns, Woody learned how radon gas permeates the lungs of miners like her uncle, eventually causing cancer. She also learned that uranium can migrate into water and can harm the kidneys.
"Back home, the San Juan River runs next to the tailings pile," she said. "People swim, fish and get water from the river."
A federal cleanup is under way at Shiprock, where the air and groundwater are being carefully monitored for contamination.
But there are an estimated 1,300 abandoned uranium mines on the reservation. Blocks from the mines have been used as building materials, and in some areas, groundwater has been contaminated.
Woody believes her work enables her to help other Navajos better understand the health hazards of uranium and take precautions.
"I want to stay in research and go back to the reservation to work," she said. "There are so many issues there."
